Inner tube.



W. M. REASON.

INNER TUBE.

APPLICATION FILED JAN.15, 191:.

Patented Sept. 8, 1914.

IHVENTOR 10% m @TTORHEY UNITED STATES PATE- .FFICE.

WALTER-M. REASON, or PON'I'LA 'MIOHIGAN.

INNER TUBE.

Specification of Letters Patent.

Patented Sept. 8, 1914.

Application filed January 15, 1914. Serial No. 812,211.

To all whom it may concern:

Be it known that I, WALTER M. REASON, citizen of the United States, residin at Pontiac, county of Oakland, State of ichigan, have invented a certain new and useful My invention relates to inner air tubes for pneumatic tires of the so-called double type in which an outer casing held firmly upon the wheel is made air-tight by an inner air-tight tube that con-forms to the inn'er' shape of the casing, and it consists in the-- construction, combination and arrangement hereinafter described in the specification and pointed out in the claims.

In the drawings: Figure 1, is a cross section of casing in dotted lines, inclosing a cross section of one form of my improved inner tube in full lines as arranged when in service. Fig. 2, is a vertical elevation-of the inner tube as inflated sufiiciently to give it a rounder contour. Figs. 3 and 4 are detached cross sectional views of modifications of the joint between the sections of the tube as hereinafter described.

Similar letters refer to similar parts.

A, represents a cross section in dotted lines of the casing.

B, represents cross section of the inner tube inflated with reference to the casing A. of the clencher type or of the straight type for detachable rims as my invention is applicable to all types of casings which require inner tubes to make them air-tight when in use.

C, represents that portion of the tube casing which is adjacent to the rim or what may be termed the rim side of the tube. D, represents that portion of the tube which is ad acent to the tread side of the-casing and which therefore may be termed the tread side or tread of the tubes. These two sides are joined at E, F so that substantially circumferentiall the joint is about one-half of the distance between the extreme of the tread side and the rim side of the tube.

In Figs. 3 and 4 I have shown a tube made up. In Fig. 3 one-ply merely, as hereinafter explained, designated D, C with It is immaterial whether the casing is a joint at E; in Fig. 4, I have "represented a two-ply tube, made up of 'two layers marked C C and D D with joint at:

E This ives a stron er tube and better joint as wi 1 be hereinafiter explained, than the forms shown in Fig. 1 with a one-ply d on the rim side and a two-ply as d, d on the tread side. Fig. 2, shows a portion of'the tubecut away so as to show thevinside of the lnner or rim half and the outer ortread half and especially the circumferential joint joining the two halves on the opposite side looking inwardly. In this re spect it will apply to any form of compound tube of one-ply or two-ply as shownand described, the joint being shown at E In'order to make this improved tube I use a fine heavy fabric impregnated with rubber and woven in the usual form to al' low elasticity in one direction only and to be substantially inelastic inthe opposite direction.- The rim or circumferential inner side of the tube is made of this elastic fabric so arranged as to be elastic circumferential of the section of the tube; in other words, at substantially right angles to the plane of the tube, or of the wheel upon which it is applied.

The tread or circumferential outer side of the tube is made of the same fabric but arranged so as to be elastic circumferentially or in a line corresponding with the plane of the rim of the wheel to which the tube is applied and substantially non-elastic at right angles to the plane of the tube. This fabric by reason of the rubber is not only elastic as stated but is air-tight and the two parts are joined together and cemented upon each side of the tube circumferentially as shown at E, E E they being united firmly and vulcanized together with vulcanizing cement so that the joint is air-tight. By this means I manufacture a tube which is only expandible or'elastic'in' cross section for a section on the rim side of the tube (which is the inner side circumferentially of the-tube) but is non-elastic circumferen under air pressure, to the casing for which it is designed, even to the extent of enlarging in diameter of its plane upon the tread side,-

and also enlarging in cross section by the cross elasticity of the rim side, so that the small amount of the entire elasticity required is fully met. At the same time I am enabled to makea practical tube that shall be suiliciently air-tight, as well as elastic as stated, but above all shall be composed of a compound of elastic material and a fabric instead of being made up entirely of pure vulcanized rubber as is the usual practice.

It is evident that in a tube of fibrous material or fabric without providing means for its compensating under air strains or air pressures that if the fabric is non-elastic circumferentially of the wheel an enormous strain would be thrown upon a portion of the tube adjacent to the tread in order to enlarge in its general diameter and adequately fill the space in the casing; on the other hand, if it is only made elastically extendible circumferentially of the wheel it will not be elastic in cross section and the Whole bursting strain of the air pressure would be thrown upon the cross sectional diameter of the tube proper and it would have to be made extremely strong in order to stand this pressure which would not be transferred to the casing. On the other hand, by making the tube one-part of which is elastic in one direction and the other part elastic in the other direction, as stated, I avoid these difficulties. It is essential, however, that the elasticity of the rim or wheel side of the tube shall be in line of the cross section of the tube proper and that the elasticity of the tread side of the tube shall be circumferential of the casing, because it is the larger cirto be accommodated by the longitudinal expansibility enlargement.

The mode of operation of this device when employed is sufficiently obvious without any further description.

It is obvious that the ends of the fabric when brought into circumferential arrangement can be united and made properly airtight by vulcanizing the same as the side joints are so made in order to form a complete air-tight tube with the usual valves and valve-stems being inserted therein in the usual form, all of which is unnecessary to illustrate or describe.

I desire to claim is:

inner tube for double tube pneumatic tires consisting of a rim side elastic solely on the side joined thereto and elastic solely longitions to form anair-tight joint, substantially as described. j

2. As a new article of manufacture, an

constructed with the larger circumferential part of said tube elastic circumferentially but non-elastic in cross section, and the inner, or smaller, circumferential part nonelastic circumferentially but elastic in cross section, substantially as described.

tion'in the presence of two witnesses.

' WALTER M. REASON.

Witnesses R. A. PARKER, VIRGINIA C. SPRATT.

cumferenee of the outer part that requires Having thus described my invention What 1. As a new article of manufacture, an

line of the cross section and an outer tread tudinally and means for uniting the twosecinner tube for double tube pneumatic tires 1 In testimony whereof, I sign this specifica- 

